Post-chemotherapy neuropathy, which is a pain caused by a chemical treatment for combating cancer, still remains today a pathology which is difficult to relieve or cure. This type of pain is to be distinguished from pain caused by cancerous tumours themselves. In fact post-chemotherapy neuropathy is induced by the anti-neoplastic agent administered to the patients for treatment purposes.
Post-chemotherapy neuropathic pains have particular semiological characteristics. Generally, these pains are characterized inter alia by a continuous, diffuse pain, without mechanical or inflammatory pattern, of burning type. Against this background of continuous pain, other symptoms can occur: spontaneous attacks of the shooting-pain type, tingling, more particularly tingling at limb extremities, or also electric discharges. The topography of these symptoms corresponds to a distribution compatible with a peripheral or central systematization. In other words the topography of these post-chemotherapy neuropathic pains is independent of the topography of the cancerous tumours.
Among the known treatments for this pain, there may be mentioned the administration of anticonvulsants, antidepressants or opiate compounds such as morphine, which was isolated right at the start of the 19th century by a German pharmacist, Friedrich Sertürner, from the opium of which it is the main constituent.
Moreover the World Health Organization recommends three levels of prescription for analgesic medicaments, a rule which proves effective in 70% of patients:
Level I: non-opioid analgesics for mild to moderate pains
Level II: weak opioid analgesics combined with non-opioids for moderate to intense pains.
Level III: strong opioid analgesics for intense to very intense pains.
However the use of the compounds currently available which make it possible to reduce pain caused by an antineoplastic treatment is not satisfactory as it requires the use of high doses of compounds, or frequent re-administration of the compound with possible development of a resistance to the compound or habituation. Moreover these anti-pain treatments can cause side effects, which are added to those already caused by the cancer.
It has therefore become necessary to find another means for treating these post-chemotherapy neuropathic pains.
Thus the problem that the invention proposes to solve is to find a novel treatment for the pain caused by treatment with an antineoplastic agent.